在控件TSkinData的skin3rd属性里面加上一行代码：TDBGridEh=Scrollbar

根据如下帮助文件解决：
Skin 3rd controls
 
Vclskin supports 3rd controls very easily, just add control class name in TSkinData.skin3rd property.

TSkindata.skin3rd support controls include Edit, Checkbox, Radiobutton, Combobox, Panel, Radiogroup, Checkgroup, Buton, Bitbtn, Speedbutton, Tab, Progress, Trackbar, Scrollbar, Embedscrollbar.

Embedscrollbar is to skin a control where a TScrollbar is embed in it. like TAdvMemo .

TSkindata.skin3rd example code
TDBCheckboxEh=Checkbox
TDBLookupCombobox=Combobox
TLMDCheckGroup=CheckGroup
TLMDRadioGroup=RadioGroup
TLMDRadiobutton=Radiobutton
TLMDGROUPBOX=Panel
TLMDEDIT=Edit

If there is a 3rd party checkbox that vclskin doesn't support , you just add one line in TSkindata.skin3rd
Class_name_checkbox=checkbox